1. Field of the Invention
The present invention relates to a network management apparatus and method, and more particularly, to a network management apparatus and method, which can easily manage devices that are dynamically added to a network and yet maintain an existing network management structure.
2. Description of the Related Art
The advance of indoor controlling technology along with the ever-growing public attention on home networks has led to the development of an increasing number of home network control techniques. In line with the development of home network control techniques, there is a rapidly increasing demand for efficiently managing devices connected to a home network, e.g., monitoring states of the devices or determining performances of the devices.
In general, Simple Network Management Protocol (SNMP), which is widely used for managing a network, allows a network manager to analyze a device to be managed and to take appropriate measures to handle the device to be managed by accessing a management information base (MIB) of the device to be managed and varying settings regarding the MIB. Here, the MIB is a database of a collection of information entities regarding the device to be managed, and the information entities are referred to as objects. The MIB is embodied as a hierarchical tree structure of the objects.
FIG. 1 is a block diagram of a conventional network management apparatus.
Referring to FIG. 1, the network management apparatus includes an agent 20 installed in a device to be managed and processing a plurality of pieces of information created or updated by the device as MIB objects, and a manager 10 installed in a device for managing the device to be managed, providing an interface via which an administrator can examine the state of a network, analyzing the device to be managed, and taking appropriate measures to handle the device to be managed according to the analysis results.
The manager 10 may obtain MIB objects regarding the state and operation time of the device to be managed through an operation ‘get’ or ‘getNext’. Particularly, due to the hierarchical tree structure, the operation ‘getNext’ is used in obtaining a lower-level MIB object of a pertinent MIB object. The manager 10 may manipulate the objects of the MIB of the device to be managed through an operation ‘set’, thereby controlling the device to be managed.
The agent 20 performs an operation ‘trap’ to respond to the operation ‘get’, ‘getNext’ or ‘set performed by the manager 10 or to notify the manager 10 of extraordinary circumstances occurring to the device to be managed, such as malfunction or breakdown of the device to be managed.
FIG. 2 is a diagram illustrating the structure of a typical MIB.
Referring to FIG. 2, an MIB includes a plurality of objects 31 (i.e., objects ‘iso’, ‘org’, and ‘dod’, ‘internet’, and etc) and a plurality of object instances 32 (i.e., ‘1’, ‘3’, ‘6’, ‘1’, and etc).
An administrator may issue a request for a predetermined object of the MIB to an agent 20 of a device to be managed or may set the predetermined object to a predetermined value by using a manager 20. The administrator may access the predetermined object according to an object identifier (OID) mapped to the predetermined object. An OID may be comprised of a string of a plurality of object instances, as illustrated in FIG. 2. For example, if the administrator attempts to access, for example, the object ‘internet’, the administrator may have to reference an OID (1.3.6.1) comprised of object instances ‘1’, ‘3’, ‘6’, and ‘1’.
MIB objects are classified as standard MIB objects and extended MIB objects. Standard MIB objects are MIB objects that can be applied in common to various types of devices, while extended MIB objects are device-specific MIB objects assigned by a manufacturer at the manufacturing time of the device. MIB objects are given different OIDs from one another. Each manufacturer may extend an existing MIB by creating MIB objects for various devices under an object ‘enterprise’ of the existing MIB according to the types and the purposes of use of the devices and assigning different OIDs to the created MIB objects. Extended MIB objects, which are enterprise-specific and device-specific, are prescribed and published by the Internet Assigned Number Authority.
Standard MIB objects are MIB objects that can be applied in common to various devices. Thus, it is relatively easy to manage standard MIB objects. However, when devices having their own MIBs are connected to a network, it is difficult to change an OID system used in an existing MIB to reflect changes made to the existing MIB due to the connection of the devices to the existing MIB because the MIBs of the devices have different structures.
In addition, the requirements to standardize MIBs of a plurality of devices in a network and to manage an entire OID system in the network make it difficult to manage a dynamic network, such as a home network including a considerable number of devices of various types.
Therefore, it is necessary to develop a network management method or apparatus which can make MIBs of devices added dynamically to a network accessible while maintaining the management of the network.
Japanese Patent Laid-Open Gazette No. 1999-205320 discloses a network management method in which an agent operates on a single virtual device supporting an entire MIB and responds to a request for access to an MIB issued by an SNMP manager. In this method, however, it is difficult to manage devices connected dynamically to a network.